Core support is requested for continuation of a research center on mental retardation and related aspects of human development. the John F. Kennedy Center proposes to continue and extend a multidisciplinary program that combines both basic and applied research approaches, appropriately balanced across biological and behavioral concepts and methods. The primary mission is to focus on important research questions to understand the mechanisms of mental retardation, intellectual development, and general issues of growth and development toward the goal of prevention and treatment. Collaborative research among biological, behavioral, and social sciences is a significant and dominant feature of the Center's effort. Research programs are clustered into four topical areas that address priorities identified by NICHD: neural development, neural plasticity, cognitive strategies, and social and communicative processes. Within these clusters the major areas of research, supported through external grants, include: (a) developmental neurobiology, (b) nutrition, teratology, and developmental pharmacology, (c) obstetrics and perinatology, (d) psychobiological processes, (e) psychological processes, (f) behavior analysis, (g) communicative processes, (h) diagnosis and early intervention, (i) socioecological processes, and (j) family and community. This research program is facilitated by a support system consisting of 5 core units: (a) administrative services, (b) computer and statistical services, (c) communication services, (d) behavioral sciences services, and (e) neuroscience laboratories.